IBM is not disclosing the deal's value, but a representative for the company in London said that one server fully integrated for the Linux operating system generally costs about €100,000 ($122,400) per processor, and the mainframes Endress + Hauser purchased each boast 36 processors.

Switzerland-based Endress+Hauser migrated its SAP enterprise resource planning applications from Unix to Linux in an effort to reduce costs and ensure application reliability, it said in a statement.

The mainframes were deployed at the company's data center in Weil am Rhein, Germany, and currently support 3,500 users.

The deal underscores the momentum behind IBM's mainframe business, it said, adding that its revenue from mainframes has grown over 30 percent year-on-year for the past three quarters.

Earlier this year IBM scored another big mainframe win in Germany, agreeing to deliver 20 zSeries 990 mainframes to German financial IT service company Sparkassen Informatik GmbH & Co. KG in a deal valued at over €100 million.